The invention relates generally to printed circuit boards.
More particularly, the invention relates to a testing arrangement for printed circuit boards.
Printed circuit boards are provided with printed conductors or circuits. A known arrangement for testing the continuity of the printed conductors has contact pins which respectively engage the ends of the printed conductors during testing. One end of each contact pin engages an end of a printed conductor while the other end of each contact pin constitutes a contact for an electrical conductor connected with a testing or measuring device. The contact pins are mounted in a carrier and are advantageously arranged on a grid. Preferably, the positions of the contact pins correspond to those of the ends of the printed conductors.
A testing arrangement of this type may, for example, have a grid of 2,000 to 20,000 locations at which contact is to be established with a printed circuit board undergoing test. It is possible to provide contact pins only at those locations of the grid where the printed circuit board is to be contacted or at all locations of the grid. In the latter case, those contact pins which are not to contact the printed circuit board can be covered with a perforate foil serving as a mask.
Testing arrangements having contact pins only at those locations where the printed circuit board is to be contacted have the disadvantage that their use is restricted to the particular series of printed circuit boards for which they were designed. This results in relatively high costs, especially for a limited run of a particular type of printed circuit board. On the other hand, testing arrangements in which contact pins are provided at all locations of a grid are difficult to construct and of high cost. This is due mainly to the fact that all locations of the grid are provided with contact pins. Furthermore, both types of testing arrangements have the disadvantage that only those locations of a printed circuit board which lie within the area of the grid and at the intersections of the grid lines can be contacted.